Nuclear Fusion: Friend or Foe?

Nuclear power station cooling towers with smoke being releasesd

The world as we know it is changing. Higher global temperatures and increased tropical storm intensities are just some of the issues which are tormenting our daily lives.

Developing countries are especially vulnerable to the devastation of climate change as their infrastructure is, quite often, not designed to withstand the damage caused by severe weather and rising sea levels.

Global warming, however, is not limited to developing countries. In England, the warmest day on record occurred as recent as 19 July 2022, leading to the deaths of hundreds of people.

The World Weather Attribution estimates that human-caused climate change made the heatwave 10 times more likely.

Throughout the past century, many researchers have been able to correlate the worldwide increase in greenhouse gas (GHG) emissions with climate change. In 2020, the burning of fossil fuels contributed roughly 76% of the total GHGs released into the atmosphere in the UK.

As if this statistic wasn’t shocking enough, Vladimir Putin has now exposed the UK’s weak energy security, with rapid energy price increases becoming the norm.

There is now an ever-growing demand for an alternative source of energy which is reliable and low carbon. One such option is the use of nuclear energy.

Traditionally, there has been much scepticism from both the UK government, and the public, about this source of energy. Nuclear energy generation in the form of fission reactors, has been around since the 1940s and is responsible for around 15% of the UK’s total energy production.

It works by bombarding unstable isotopes (types of atoms which have the same atomic number but have different numbers of neutrons) with high-speed particles, causing them to split. This splitting reaction releases a great deal of energy in the form of heat and radiation, which is then usually extracted from the reactor by circulating water. Finally, the heat is used to generate steam which drives turbines, resulting in the production of electricity.

Tennessee Valley Authority, Public domain, via Wikimedia Commons

This form of energy generation does not release harmful GHGs into the atmosphere and produces a large amount of energy from a relatively small amount of fuel.

Nonetheless, it does produce radioactive waste from a multitude of sources, including the fuel rods. A small portion of this waste must be stored for thousands of years until it is deemed safe. Unreliable storage of such components can result in disastrous damage to human health and the environment.

Furthermore, numerous nuclear accidents have occurred due to poor design and/or unsafe operation of the reactors, resulting in a devastating loss of life. Such past accidents have led to an increased hesitation regarding the construction of new fission plants.

Nuclear fusion promises to be a much safer and efficient form of nuclear energy generation. Whilst it is currently an experimental form of energy, it is hoped that nuclear fusion can be commercialised within the next few decades.

Conversely to fission reactors, fusion energy is produced when two, low-mass isotopes unite under conditions of extreme temperature and pressure. As with nuclear fission, the fusion reaction does not produce any harmful GHG emissions.

The Joint European Torus tokamak reactor uses a Deuterium-Tritium fuel mix which combines to produce a helium nucleus, a neutron, and 17.6 MeV of energy. This is around four times larger than the amount of energy released by nuclear fission and around four million times more energy than the equivalent reaction during the burning of gas and coal.

A tokamak is a magnetic inertial confinement device which uses a powerful magnetic field to shape plasma and confine it away from the reactor walls. The word itself comes from a Russian acronym which means “toroidal chamber with magnetic coils.”

There are also numerous other benefits to the use of fusion reactors for energy generation. This type of reactor does not produce any long-lived radioactive waste, which allows all waste components to be recycled or reused within a span of 100 years.

The risk of nuclear meltdown, as seen in the Chernobyl disaster, is also non-existent, as fusion reactors would automatically cease operation should there be a change in working configuration.

Nuclear waste sign

Fusion reactors do, however, come with their own set of drawbacks. Whilst long-lived nuclear waste is not produced, radioactive components are still required to be carefully stored for many years in specific and controlled conditions.

Furthermore, current experiments in fusion, such as the ITER experiment in France, have shown that the reactors have a very large ‘parasitic power consumption’. This means that a large amount of the generated power is used for auxiliary purposes such as heating and water pumping.

Nonetheless, there is good news on the fusion energy horizon.

Earlier this year, EUROFusion scientists working at the JET facility in Oxfordshire, produced 59 megajoules of sustained energy over a five second duration, which is enough energy to boil 60 kettles. This smashed the previous world record set by JET in 1997, producing double the amount of energy.

‘The record, and more importantly the things we’ve learned about fusion under these conditions and how it fully confirms our predictions, show that we are on the right path to a future world of fusion energy,’ said Tony Donné, EUROfusion Programme Manager. ‘If we can maintain fusion for five seconds, we can do it for five minutes and then five hours as we scale up our operations in future machines.

Such promising data would not be possible without the continued support of governments and donors, who are now becoming aware of the benefits of nuclear fusion.

More money has been invested in fusion over the last year than in the previous 10 years combined. The UK government has recently pledged an investment of more than £220 million for the construction of a spherical tokamak reactor at the West Burton A power plant. It is hoped that this will come into operation in the early 2040s.

Spherical tokamak reactors are not the only type of fusion reactor with encouraging results. Oxford University spin-off company, First Light Fusion, have achieved a fusion reaction using their state-of-the-art projectile technique, which was confirmed by the UKAEA.

The $45 million gained from new and existing investors in 2022, will be used to accelerate progress on First Light Fusion’s ‘gain’ experiment, whereby the amount of energy required to spark the reaction will be surpassed by that which is produced.

In 2021, scientists at the US Department of Energy also produced over 10 quadrillion watts of fusion power in over a fraction of a second. This utilised a laser-based, inertial confinement fusion device, which involves the use of heated and compressed thermonuclear fuel.

All in all, nuclear fusion presents a viable alternative to the use of fossil fuels for energy generation.

Whilst initial data is promising, the first commercial fusion reactors are still years away. Global energy demand is projected to increase by 50% up to the year 2050, so it is still imperative that other sources of energy are used to keep up with the demand of the grid.

Yet, with the promising experimental data shown in this article, a carbon neutral future could be achieved within the next few decades.